Nano-fabrication includes the fabrication of very small structures that have features on the order of 100 nanometers or smaller. One application in which nano-fabrication has had a sizeable impact is in the processing of integrated circuits. The semiconductor processing industry continues to strive for larger production yields while increasing the circuits per unit area formed on a substrate, therefore nano-fabrication becomes increasingly important. Nano-fabrication provides greater process control while allowing continued reduction of the minimum feature dimensions of the structures formed.
During imprint lithography, precise alignment of the substrate relative to the template is desired to minimize production defects. Typically this alignment may involve complicated or expensive interferometric devices which are difficult to calibrate, expensive to maintain, and can be inaccurate depending on the location of these devices. Furthermore, it has proven difficult to obtain adequate imagery of substrates during imprint lithography.